The plan sought to cut emissions from power plants in 47 US states to 32% below 2005 levels by 2030. But it was stayed by the Supreme Court in February 2016, pending the results of litigation related to the regulation.

In a letter that Pruitt sent to governors across the US on March 30, the EPA chief wrote that states have "no obligation to spend resources" on the stayed order — adding, "the days of coercive federalism are over."

In effect, Pruitt is telling the governors that even though it could take years to take the Clean Power Plan off the books (and handle any court challenges during that process), states can treat the plan as though it's already dead and buried.

On February 9, 2016, the Supreme Court stayed implementation of the Clean Power Plan pending judicial review. The Court's decision was not on the merits of the rule. EPA firmly believes the Clean Power Plan will be upheld when the merits are considered because the rule rests on strong scientific and legal foundations. For the states that choose to continue to work to cut carbon pollution from power plants and seek the agency's guidance and assistance, EPA will continue to provide tools and support.